The present invention is directed to creating simulated, photographic-quality prints and substrates suitable for use in creating simulated photographic-quality images or prints using imaging such as xerography and/or ink jet printing and/or copying. More specifically, the present invention is directed to creating simulated, photographic-quality prints which resist color degradation due to Ultra Violet (UV) light.
In the practice of conventional xerography, it is the general procedure to form electrostatic latent images on a xerographic surface by first uniformly charging a charge retentive surface such as a photoreceptor. The charged area is selectively dissipated in accordance with a pattern of activating radiation corresponding to original images. The selective dissipation of the charge leaves a latent charge pattern on the imaging surface corresponding to the areas not exposed by radiation.
This charge pattern is made visible by developing it with toner by passing the photoreceptor past one or more developer housings. In monochromatic imaging, the toner generally comprises black thermoplastic powder particles which adhere to the charge pattern by electrostatic attraction. The developed image is then fixed to the imaging surface or is transferred to a receiving substrate such as plain paper to which it is fixed by suitable fusing techniques.
Recently, there has been a great deal of effort directed to the development of color copiers/printers which utilize the xerographic and/or ink jet imaging process. Such efforts have resulted in the introduction of the Xerox.TM. 5775.TM. copier/printer, the Xerox 4900.TM. and the Fuji Xerox A-Color 635.TM. machine into the market place.
Notwithstanding all the recent development in the area of color printers and copiers there is room for improvement in the quality of color images on paper and synthetic substrates such as Mylar.TM. and Teslin.TM.. The foregoing is particularly true when trying to create photographic-quality images using non photographic processes.
Attempts at improving conventionally formed color toner images have led to the lamination of xerographic images on paper using a transparent substrate. This procedure has been only partially successful because the lamination process tends to reduce the density range of the print resulting in a print that has less shadow detail. The lamination process also adds significant weight and thickness to the print.
Additionally, it is believed that the aforementioned lamination process doesn't produce good results because typically the color toner images at the interface between the laminate and the toner do not make suitable optical contact. That is to say, the initially irregular toner image at the interface is still irregular (i.e. contains voids) enough after lamination that light is reflected from at least some of those surfaces and is precluded from passing through the toner. In other words, when there are voids between the transparency and toner image, light gets scattered and reflected back without passing through the colored toner. Loss of image contrast results when any white light is scattered, either from the bottom surface of the transparent substrate or from the irregular toner surfaces and doesn't pass through the toner.
A known method of improving the appearance of color xerographic images on a transparent substrate comprises refusing the color images. Such a process was observed at a NOMDA trade show in 1985 at a Panasonic exhibit. The process exhibited was carried out using an off-line transparency fuser, available from Panasonic as model FA-F100, in connection with a color xerographic copier which was utilized for creating multi-color toner images on a transparent substrate for the purpose of producing colored slides. Since the finished image from the color copier was not really suitable for projection, it was refused using the aforementioned off-line refuser. To implement the process, the transparency is placed in a holder intermediate which consists of a clear relatively thin sheet of plastic and a more sturdy support. The holder is used for transporting the imaged transparency through the off-line refuser. The thin clear sheet is laid on top of the toner layer on the transparency. After passing out of the refuser, the transparency is removed from the holder. This process resulted in an attractive high gloss image useful in image projectors. The refuser was also used during the exhibit for refusing color images on paper. However, the gloss is image-dependent. Thus, the gloss is high in areas of high toner density because the toner refuses in contact with the clear plastic sheet and becomes very smooth. In areas where there is little or no toner the gloss is only that of the substrate. The refuser was also used during the exhibit for refusing color images on paper.
Following is a discussion of additional prior art which may bear on the patentability of the present invention. In addition to possibly having some relevance to the question of patentability, these references, together with the detailed description to follow, should provide a better understanding and appreciation of the present invention. The prior art discussed herein as well as the prior art cited therein is incorporated herein by reference.
U.S. Pat. Nos. 5,327,201 and 5,337,132 granted to Robert E. Coleman on Jul. 5, 1994 and to Abraham Cherian on Aug. 9, 1994, respectively, disclose the creation of simulated photographic prints using xerography. To this end, reverse reading images are formed on a transparent substrate and backing sheet is adhered to the transparent substrate. U.S. patent applications Nos. 08/095,639, 08/095,622, 08/095,016, 08/095,136 and 08/095,639 cited in the '132 patent are also incorporated herein by reference.
Protective sheets used in various printing and imaging processes are well known. For example, U.S. Pat. No. 5,418,208 (Takeda and Kawashima) discloses a laminated plastic card providing a lamination of a dye accepting layer, a substrate of paper or the like, and a back coat layer on which lamination one or more patterns are printed with a volatile dye, and a transparent plastic film adhered on the lamination by an adhesive agent, wherein the adhesive agent is a saturated polyester having an average molecular weight of 18,000 gm/mole and produced by condensation polymerization of polypropylene glycol or trimethylol propane and adipic acid or azelaic acid.
U.S. Pat. No. 5,413,840 (Mizuno) discloses a decorative laminated sheet having a sense of being coated and having improved surface hardness, which is produced by laminating a polyester film excellent in transparency on the surface of a semi-rigid thermoplastic resin film supplied with a colored layer or a pattern-printed layer, and then coating a hard coat layer comprising a UV-curable coating on the surface of the polyester film of the resulting laminated film, and a process for producing the same. This invention can provide a sheet not only excellent in scratch resistance, specular reflectivity and sharpness of the surface, but having a sense of being deeply coated as well.
U.S. Pat. No. 5,378,536 (Miller and Clements) discloses a repositionable adhesive tape where an adhesive of certain elastomeric block copolymers and tackifying materials can be hot-melt coated on to a flexible backing to provide an adhesive tape, two pieces of which can bond to each other to have excellent resistance to shear forces but can be easily peeled apart, even after prolonged periods of time. The adhesive can be low-tack or tack-free. When the novel adhesive is tacky, it can bind sheets into a note pad from which individual sheets can be removed, temporarily adhered to paper and other substrates, and later cleanly removed, even after prolonged contact.
U.S. Pat. No. 5,352,530 (Tanuma et.al) discloses a highly transparent film having high strength, suitable extensibility, high weather resistance, low moisture absorption, which consists mainly of ethylene-vinylacetate copolymer. Various laminates making the most of the above properties of the film are disclosed, which comprise the ethylene-vinylacetate copolymer interposed between two inorganic material sheets, two organic material sheets, or an inorganic material sheet and an organic material sheet.
U.S. Pat. No. 5,346,766 (Otter and Watts) discloses a positionable-repositionable pressure sensitive adhesive that may be repeatedly applied to a surface and removed during an initial installation time period. The adhesive contains an adhesive base resin and coacting detackifying resin and particulate components which temporarily reduce the tack and peel strength of the adhesive. Upon passage of time and/or application of thermal energy, adhesion build-up occurs to a maximum value. The pressure-sensitive adhesive may be used as an adhesive layer in a laminate for tapes, # signs and decorative and protective applications including vehicle marking and architectural installations.
U.S. Pat. No. 5,342,685 (Gobran) discloses a hot melt coatable pressure-sensitive adhesive showing high levels of adhesion to low surface energy films and nonwovens. The adhesive elastomeric phase comprises from 78 to 98 parts by weight of a diblock A-B type block copolymer with an elastomeric block of 1,3-polybutadiene with 2 to 22 parts by weight of multiblock A-B type block copolymer. The tackifying material comprises 140 parts or less of a solid tackifying resin and a liquid tackifier to provide an adhesive having a composite midblock glass transition of -10.degree. C.
U.S. Pat. No. 5,118,570 (Malhotra) and U.S. Pat. No. 5,006,407 (Malhotra), the disclosures of each of which are totally incorporated herein by reference, disclose a transparency which comprises a hydrophilic coating and a plasticizer, which plasticizer can, for example, be from the group consisting of phosphates, substituted phthalic anhydrides, glycerols, glycols, substituted glycerols, pyrrolidinones, alkylene carbonates, sulfolanes, and stearic acid derivatives.
U.S. Pat. No. 4,526,847 (Walker et al.) discloses a transparency for the formation of an adherent electrostatic image thereon which includes a polyester resin film sheet having an image-receiving coating of nitrocellulose, a plasticizer, a particulate material, and, preferably, an antistatic agent. The coating is applied to the film sheet from a solvent mixture of an aliphatic ester or an aliphatic ketone, and an aliphatic alcohol.
U.S. Pat. No. 3,561,337 (Mulkey) discloses a sheet material having a transparent backing coated with a layer containing a polymeric binder and particles of solid material which is insoluble in the binder. The refractive index of the solid material varies from that of the binder by at most .+-.0.6. The surface of the layer is ink receptive and, by printing on that surface, a transparency is obtained.
U.S. Pat. No. 3,488,189 (Mayer et al.) discloses the formation of fused toner images on an imaging surface corresponding to an electrostatic field by depositing on the imaging surface in image configuration toner particles containing a thermoplastic resin, the imaging surface carrying a solid crystalline plasticizer having a lower melting point than the melting range of the thermoplastic resin and heat fusing the resulting toner image.
U.S. Pat. No. 4,956,225 (Malhotra) discloses a transparency suitable for electrographic and xerographic imaging which comprises a polymeric substrate with a toner receptive coating on one surface. Also disclosed are transparencies with first and second coating layers.
U.S. Pat. No. 4,997,697 (Malhotra) discloses a transparent substrate material for receiving or containing an image which comprises a supporting substrate base, an antistatic polymer layer coated on one or both sides of the substrate and comprising hydrophilic cellulosic components, and a toner receiving polymer layer contained on one or both sides of the antistatic layer, which polymer comprises hydrophobic cellulose ethers, hydrophobic cellulose esters, or mixtures thereof, and wherein the toner receiving layer contains adhesive components.
U.S. Pat. No. 5,202,205 (Malhotra), discloses a transparent substrate material for receiving or containing an image comprising a supporting substrate, an ink toner receiving coating composition on both sides of the substrate and comprising an adhesive layer and an antistatic layer contained on two surfaces of the adhesive layer, which antistatic layer comprises mixtures or complexes of metal halides or urea compounds both with polymers containing oxyalkylene segments.
U.S. Pat. No. 5,244,714 (Malhotra et al.), discloses a recording sheet which comprises a base sheet, an antistatic layer coated on at least one surface of the base sheet comprising a mixture of a first component selected from the group consisting of hydrophilic polysaccharides and a second component selected from the group consisting of poly (vinyl amines), poly (vinyl phosphates), poly (vinyl alcohols), poly (vinyl alcohol)-ethoxylated, poly (ethylene imine)-ethoxylated, poly (ethylene oxides), poly (n-vinyl acetamide-vinyl sulfonate salts), melamine-formaldehyde resins, urea-formaldehyde resins, styrene-vinylpyrrolidone copolymers, and mixtures thereof, and at least one toner receiving layer coated on an antistatic layer comprising a material selected from the group consisting of maleic anhydride containing polymers, maleic ester containing polymers, and mixtures thereof.
U.S. Pat. No. 5,302,439 entitled "Recording Sheets" with the named inventors Shadi L. Malhotra and Brent S. Bryant, discloses a recording sheet which comprises (a) a substrate; (b) a coating on the substrate which comprises a binder and a material having a melting point of less than about 65.degree. C and a boiling point of greater than 150.degree. C. and selected from the group consisting of alkyl phenones, alkyl ketones, halogenated alkanes, alkyl amines, alkyl anilines, alkyl diamines, alkyl alcohols, alkyl diols, halogenated alkyl alcohols, alkane alkyl esters, saturated fatty acids, unsaturated fatty acids, alkyl aldehydes, alkyl anhydrides, alkanes, and mixtures thereof; (c) an optional traction agent; and (d) an optional antistatic agent.
U.S. Pat. No. 5,451, 466 entitled "Recording Sheets" with the named inventor Shadi L. Malhotra, discloses a recording sheet which comprises (a) a substrate; (b) a coating on the substrate which comprises (i) a binder selected from the group consisting of (A) copolymers of styrene and at least one other monomer; (B) copolymers of acrylic monomers and at least one other monomer; and (C) mixtures thereof; and (ii) an additive having a melting point of less than about 65.degree. C. and a boiling point of more than about 150.degree. C. and selected from the group consisting of (A) diphenyl compounds; (B) phenyl alkanes; (C) indan compounds; (D) benzene derivatives; (E) benzyl alcohols; (F) phenyl alcohols; (G) menthol; (H) aromatic amines; and (I) mixtures thereof; (c) an optional filler; (d) an optional antistatic agent; and (e) an optional biocide. Also disclosed is a process for generating images which comprises (1) generating an electrostatic latent image on an imaging member in an imaging apparatus; (2) developing the latent image with a toner which comprises a colorant and a resin selected from the group consisting of (A) copolymers of styrene and at least one other monomer; (B) copolymers containing acrylic monomers and at least one other monomer; and (C) mixtures thereof; and (3) transferring the developed image to a recording sheet which comprises (a) a substrate; (b) a coating on the substrate which comprises (i) a polymeric binder selected from the group consisting of (A) copolymers of styrene and at least one other monomer; (B) copolymers of acrylic monomers and at least one other monomer; and (C) mixtures thereof; and (ii) an additive having a melting point of less than about 65.degree. C. and a boiling point of more than about 150.degree. C. and selected from the group consisting of (A) diphenyl compounds; (B) phenyl alkanes; (C) indan compounds; (D) benzene derivatives; (E) benzyl alcohols; (F) phenyl alcohols; (G) menthol; (H) aromatic amines; (I) aliphatic amines; (J) aldehydes; (K) aldehyde derivatives; and (L) mixtures thereof; (c) an optional filler; (d) an optional antistatic agent; and (e) an optional biocide.
South African Patent Application 924,610 discloses a transparent recording sheet suitable for making visual transparencies which comprises a thin transparent film backing bearing on at least one major surface thereof an ink jet receptive layer comprising from 1% to 10% of at least one acid having a pKa of from 2 to 6, said acid being selected from the group consisting of aryl monocarboxylic acids, aryloxy monocarboxylic acids, alkyl carboxylic acids having alkyl groups containing at least 11 carbon atoms, dicarboxylic acids, tricarboxylic acids, and pyridinium salts, and at least one liquid-absorbent polymer comprising from 90% to 99% aprotic constituents, wherein said sheet shows reduced fading when imaged with an ink containing triarylmethane dye and at least one nucleophile over an identical composition containing no protic organic-solvent-soluble additive.
U.S. Pat. No. 5,500,668 with the named inventors Shadi L. Malhotra, Kurt B. Gundlach, and Richard L. Colt, filed concurrently herewith, entitled "Recording Sheets for Printing Processes Using Microwave Drying" discloses a printing process which comprises (a) providing a recording sheet which comprises a substrate, at least one monomeric salt, an optional binder, an optional antistatic agent, an optional biocide, and an optional filler; (b) applying an aqueous recording liquid to the recording sheet in an imagewise pattern; and (c) thereafter exposing the substrate to microwave radiation, thereby drying the recording liquid on the recording sheet.
Copending application U.S. Ser. No. 08/196,922 (Attorney Docket No. D/93594), with the named inventor Shadi L. Malhotra, filed concurrently herewith, entitled "Recording Sheets Containing Alcohols and Saccharides" discloses a recording sheet which comprises a substrate and a material selected from the group consisting of monosaccharides, oligosaccharides, and mixtures thereof, thereby drying the recording liquid on the recording sheet.
U.S. Pat. No. 5,589,277 with the named inventor Shadi L. Malhotra, filed concurrently herewith, entitled "Recording Sheets Containing Amino Acids, Hydroxy Acids, and Polycarboxyl Compounds" discloses a recording sheet which comprises a paper substrate and a material selected from the group consisting of monomeric amino acids, monomeric hydroxy acids, monomeric polycarboxyl compounds, and mixtures thereof. Another embodiment is directed to a recording sheet which comprises a substrate and an additive material selected from the group consisting of monomeric amino acids, monomeric hydroxy acids, and mixtures thereof.
Copending application U.S. Ser. No. 08/196,607 (Attorney Docket No. D/93598), with the named inventor Shadi L. Malhotra, filed concurrently herewith, entitled "Recording Sheets Containing Amine Salts and Quaternary Choline Halides" discloses a recording sheet which comprises a substrate and a material selected from the group consisting of monomeric amine acid salts, monomeric quaternary choline halides, and mixtures thereof.
Copending application U.S. Ser. No. 08/196,676 (Attorney Docket No. D/93599), with the named inventor Shadi L. Malhotra, filed concurrently herewith, entitled "Recording Sheets Containing Pyrrole, Pyrrolidine, Pyridine, Piperidine, Homopiperidine, Quinoline, Isoquinoline, Quinuclidine, Indole, and Indazole Compounds" discloses a recording sheet which comprises a substrate and an additive material selected from the group consisting of pyrrole compounds, pyrrolidine compounds, pyridine compounds, piperidine compounds, homopiperidine compounds, quinoline compounds, isoquinoline compounds, quinuclidine compounds, indole compounds, indazole compounds, and mixtures thereof.
Copending application U.S. Ser. No. 08/196,933 (Attorney Docket No. D/93600), with the named inventor Shadi L. Malhotra, filed concurrently herewith, entitled "Recording Sheets Containing Purine, Pyrimidine, Benzimidazole, Imidazolidine, Urazole, Pyrazole, Triazole, Benzotriazole, Tetrazole, and Pyrazine Compounds" discloses a recording sheet which comprises a substrate and a material selected from the group consisting of purine compounds, pyrimidine compounds, benzimidazole compounds, imidazolidine compounds, urazole compounds, pyrazole compounds, triazole compounds, benzotriazole compounds, tetrazole compounds, pyrazine compounds, and mixtures thereof. Also disclosed is a recording sheet which consists essentially of a substrate, at least one material selected from the group consisting of purine compounds, pyrimidine compounds, benzimidazole compounds, imidazolidine compounds, urazole compounds, pyrazole compounds, triazole compounds, benzotriazole compounds, tetrazole compounds, pyrazine compounds, and mixtures thereof, an optional binder, an optional antistatic agent, an optional biocide, and an optional filler.
U.S. Pat. No. 5,663,004 with the named inventors Shadi L. Malhotra, Brent S. Bryant, and Arthur Y. Jones, filed concurrently herewith, entitled "Recording Sheets Containing Mildew Preventing Agents" discloses a recording sheet which comprises a substrate, an image receiving coating, and a biocide.
U.S. Pat. Nos. 4,686,163 and 4,600,669 describe an electrophotographic imaging method that uses an element comprising a photoconductive layer on an electrically conducting substrate capable of transmitting actinic radiation to which the photoconductive layer is responsive, and a dielectric support, releasably adhered to the substrate, comprising the photoconductive layer or an overcoat thereof forming a surface of the element capable of holding an applied electrostatic charge. To use the element, the surface of the dielectric support is charged, and the photoconductive layer is imagewise-exposed to actinic radiation, thereby forming a developable electrostatic image on the dielectric surface. The electrostatic image, in turn, is developed with toner to form a first color image. A composite color image is formed on the element by repeating the sequence one or more times with imagewise exposure of the photoconductive layer to actinic radiation transmitted through the substrate, and developing over each preceding image with a different color toner. The composite tone image is transferred with the dielectric support to a receiving element to form a color copy such as a three-color filter array or a color proof closely simulating the color print expected from a full press run.
The dielectric support on the photoconductive layer comprised a transparent blend of (vinylacetate-co-crotonic acid, 95/5 mole ratio) and cellulose acetate butyrate. The resulting multicolor proof presented a multicolor toner image against a white paper background and protected by the overlying dielectric support, thus accurately resembling a multicolor print from a full press run.
The receiver element to which the dielectric support and composite toner image are transferred can be any suitable material against or through which the toner image is desired to be viewed. The receiver can be print stock, such as paper, upon which a press run will be conducted. The receiver can also be of transparent material such as a polymeric film. With respect to the latter, the invention also contemplates, as an embodiment, transfer of the composite toner image and dielectric support to image-bearing elements such as microfilm or microfiche so that the composite color image forms information in addition to image information already present on such image-bearing elements. In addition, the invention contemplates the use of transparent glass or non birefringent translucent polymeric materials such as cellulose esters for use as the receiver. Receivers manufactured from such materials are suited for use informing three-color filter arrays by the process described herein involving the formation of filter array matrices of the complementary colorants cyan, magenta and yellow in the respective color toner imaging steps. If desirable, the receiver can also contain a suitable overcoat layer adapted to soften under the influence of pressure and heat during the transfer step. In this manner, the adhesion of the dielectric support and composite toner image to the receiver can be enhanced.
The electrophotographic element bearing the multicolor toner image is moved to a separate lamination device comprising heated metal and rubber rolls, together forming a nip. The toner image is passed through the nip with and against a white receiver paper at a roll temperature of 100.degree. C. (212.degree. F.) and a pressure of 225 pounds per square inch to effect transfer of the dielectric support and composite image to the receiver followed by peeling off the rest of the electrophotographic element.
U.S. Pat. No. 4,066,802 granted on Jan. 3, 1978 to Carl F. Clemens discloses a method of decalcomania in which a toner image pattern is formed on a transfer member which has been overcoated with an adhesive material. A polymeric sheet is interposed between the toner image and a cloth or other image receiving medium. The polymeric sheet assists in the permanent adherence of the toner imaging pattern to the cloth material or other medium when the composite is subjected to heat and pressure. The transfer member and method of its use are set forth. Another embodiment discloses the use of a solvent to fix the image to a cloth material.
U.S. Pat. No. 5,065,183 granted on Nov. 12, 1991 to Morofuji et al. discloses a multicolor printing method for printing multicolor picture images upon a material or object to be printed comprises the steps of, in accordance with a first embodiment of the invention, the formation of a multicolor toner image upon a flexible belt by means of electrophotographic printing methods or techniques, and the transfer of such multicolor toner image directly to the material or object to be printed, such as, for example, a container made of, for example, metal, paper, plastic, glass, or the like, by means of a thermo-transferring process. In accordance with a second embodiment of the invention, the multicolor toner image is formed upon a plastic film, which is laminated upon the flexible belt, by means of electrophotographic printing methods or techniques, and the plastic film is then transferred to and fused upon the container. In accordance with a third embodiment of the invention, a photoconductive member is irradiated by means of exposure light upon a rear surface thereof wherein the multicolor picture images are also formed by electrophotographic printing methods or techniques. In this manner, previously formed toner images upon the photoconductive member do not interfere with the image exposure processing.
U.S. Pat. No. 5,126,797 granted on Jun. 30, 1992 to Forest et al. discloses a method and apparatus for laminating toner images wherein a toner image on a receiving sheet is laminated using a transparent laminating sheet fed from the normal copy sheet supply of a copier, printer or the like. The laminating sheet is fed into laminating contact with the toner image after the toner image has been formed on a receiving sheet. The resulting sandwich is fed through the fuser laminating the image between the sheets. The invention is particularly usable in forming color transparencies.
U.S. Pat. No. 5,108,865 granted to Zwaldo et al on Apr. 28, 1992 discloses a method including the steps of: contacting an image (preferably multi-toned image) with a transfer web(intermediate receptor layer) comprising in sequence, a carrier layer, a transferable release layer, and a releasable adhesive layer (releasable from the carrier layer along with the transferable release layer so that both layers transfer at once), said adhesive layer being in contact with said toned image, said contacting being done under sufficient heat and/or pressure to enable said toned image to be adhered to said releasable adhesive layer with greater strength than the adherence of said toned image to said imaging surface of said photoconductive layer; separating the transfer web and said photoconductive layer so that the toned image is removed from said photoconductive layer and remains adhered to the adhesive layer of the transfer web; contacting the surface of the transfer web having both the multi-toned image and adhesive thereon with a permanent receptor removing the carrier layer of the transfer web from the adhesive and the release layer of the transfer web so that an image article is formed of the permanent receptor, multi-toned image, releasable adhesive, and the resultant surface coating of the release layer which is furthest away from the permanent receptor.
U.S. Pat. Nos. 4,868,049 and 4,724,026 granted to Marshall A. Nelson on Feb. 9, 1988 and Sep. 19, 1989, respectively disclose selective metallic transfer foils for selectively transferring metallic foil to xerographic images on are receiving substrate such as paper. The transfer sheet comprises, in successive layers, a carrier film, a metallic film and an adhesive, the adhesive containing a dispersion of 0.5 micron or larger particulate material. A method is disclosed for forming images overlaid with metallic foil. According to the method of the invention, a sheet comprising xerographic images is provided and placed in face-to-face contact with a metal transfer sheet, to form a sandwich with the xerographic images on the inside. Heat and pressure are applied to the sandwich, causing the xerographic images to become tacky and causing the metallic foil to selectively adhere to the images. The remainder of the transfer sheet is then stripped away from the resulting decorated sheet comprising xerographic images overlaid with metallic foil.
U.S. Pat. No. 3,914,097 granted to Donald R. Wurl on Oct. 21, 1975 discloses a sheet guide and cooling apparatus for preventing curl in sheets bearing a developed image, the image being permanently fixed to the sheet by application of heat and pressure. The apparatus is positioned to have a flat thermally conductive surface establishing a path for the sheet, downstream of the fixing area, the path extending in a plane substantially coplanar with the plane of sheet travel in the fixing station. Vacuum means associated with the surface maintains successive incremental portions of a sheet in face-to-face contact with the flat surface as it is being guided for at least a predetermined period as the sheet moves along the path and furthermore, provides a flow of cooling air for the surface.
U.S. patent application Ser. No. 07/828,821 filed on Sep. 31, 1992 discloses a method and apparatus for enhancing color fidelity in a printing process employing an intermediate member wherein a developing unit deposits a colorless and transparent material directly onto an intermediate member before transfer of any color toner images thereto. Alternatively, a developing unit first deposits the colorless and transparent material on a latent image member. The colorless and transparent material is then transferred to the intermediate member before transfer of any color toner images thereto.
U.S. Pat. No. 5,663,023 relates to coated sheets or substrates such as paper, opaque Mylar, Teslin or the like which are utilized in the creation of simulated, photographic-quality prints formed using non photographic imaging procedures such as xerography and ink jet. A first substrate has a reverse reading image formed thereon. Such an image may be formed using conventional color xerography. A second substrate having a right reading image containing the same information as the first substrate is adhered to the first substrate. The foregoing results in a simulated photographic-quality print which has a relatively high optical density compared to prints using only the reverse reading image on the one substrate.
There is a continuing need for improved coated backing sheets which can be laminated by the application of heat and pressure to the toned images obtained from electrophotographic imaging processes as well as ink jet printing processes.